In ancient Grece « νανος » (nanos) refers to the world of dwarves. In this miniature world, objects are already complex assemblies of many atoms.

Today, nano is first a unit of length, on billionth (10^-9) of a meter. This is a size close to the diameter of a carbon nanotube or the diameter of ADN double helix, which contains the information of the genetic code. It is also the size of a great number of organic molecules.

Représentation d’un nanotube de carbone

A carbon nanotube is a single sheet of graphite (graphene) made up of carbon atom arranged in a honeycomb lattice and rolled on itself. If its diameter is only one naometer, in comparison, its length can be considerable (nearly a centimeter, 10 million times longer !). This material has electrical properties which are so exceptionnal that one is considering using it in electrical components (to make flexible TV screens).

Représentation d’une double hélice d’ADN

adn is a complex biological molecule which contains the genetic information. It is made of two helices connected by spoke-bridges (made by matching strands of Adelin/Thymin and Cytosin/Guanin). The matching of strands are at the basis of the recognition of biological objects. The overall dimension of a biological strand Les brins complémentaires sont à la base de la reconnaissance et of an adn strand is 110 nanomèter (one tenth of a micron), but if one would “unfold” the strand on a line, its length wooed exeed the centimeter !.

There are many other examples of nano-objects coming from chemistry or magnetism. Most of these objects have the same size and can be observed with the same tools. Fabrication techniques and assembly methods share also some similarities.

This is why scientific discipline converge at the nanometer-scale. On this scale, some of the concepts and observation techniques are shared by all natural sciences. nanoscience is in essence a pluridisciplinary field.